Skip to main content

Full text of "Lumnite for overnight concrete."

See other formats


/2 






Ifr 



* 






I 






' 





\ 












[BLANK PAGE] 



\ 




CCA 



INTFRNATIQNAI 






■ 









- ^ 



• 






t 



' 




UMNITE 



for 



Overnight 



Concrete 




The Atlas Lumnite Cement Company 

United States Steel Corporation Subsidiary 



Chrysler Building, New York 



208 South LaSalle Street, Chicago 




Copyright 1941', The Atlas Lumnite Cement Company 



Printed in U.S. A 




United States Navy Pier, Puget 
Sound Navy Yard, Bremerton, 
Wash. 50 ton cylinders precast and 
ready to place after 24 hours. 240 
of these cylinders required about 
9000 barrels of LUMNITE. 



I 




Materials for Overnight Concrete 



Aggregates 



Admixtures 



Mixing 

Water 



For structural concrete in ordinary service the same aggregates may be 
used as with portland cement. Clean, hard sand, gravel and crushed 
stone are suitable provided that they are well graded from fine to coarse 
as required for good portland cement concrete. Light-weight aggre- 
gates, such as Haydite and processed slags may be used. 

Other cements, lime, anti- freezing compounds, accelerating admixtures 
and soluble compounds in general should not be mixed with LUMNITE. 
The mixer, wheelbarrows and other tools should be clean and free from 
other cements, lime or soluble materials. Contamination by such ma- 
terials may affect the setting and hardening, resulting in concrete which 
is unworkable or which fails to harden after placing. 

Most mineral pigments used for coloring concrete can be used with 
LUMNITE. If in doubt, trial mixes should be made with the coloring 
materials to ascertain their effect on the setting and hardening time. 

Use the least amount of water possible. Excess mixing water is harmful. 
If a workable mix cannot be obtained without excess water, plasticity 
can generally be improved by increasing the quantity of sand or de- 
creasing the quantity of coarse aggregate in the mix. 

For concrete do not use more than 7 gallons of water per sack of 
LUMNITE, for mortar not more than 5 gallons of water per sack of 
LUMNITE, including the moisture in the aggregate in these quantities 
in each case. Use less wherever possible. Wash water used for clean- 
ing mixer should not be included in the mixing water. 




Page 5 




Effect of Quantity of Mixing Water on Compressive Strength 

1:2:4 LUMNITE Concrete 



Gal. Water per 
Bag LUMNITE 

5.26 
6.00 
7.53 
9.41 



Compressive Strength 

at 24 hours 

5253 psi 
4466 
3258 
1809 



Use Least Possible Mixing Water 



The approximate quantity of moisture carried by average aggregates may 
be estimated from the following table. An accurate determination for 
the aggregates on the job should be made when possible. 

Very wet sand % to 1 gal. per cu. ft. 

Moderately wet sand-— —about l / 2 gal. per cu. ft. 

Moist sand . about l / 4 gal. per cu. ft. 

Moist gravel or crushed rock about l / 4 gal. per cu. ft. 

All materials, including the water, should be accurately measured. Use MGQSUrilltf 



a cubic-foot box or other container of known capacity to measure the 



aggregate. One bag of LUMNITE 
or seven and one-half gallons. 



94 pounds or one cubic foot 



Batches should be machine mixed from one to one and one-half minutes 
after all materials, including the water, are in the mixer. Prolonged 
mixing is harmful. Do not mix more than 1 l /z minutes. Be sure the 
mixer is clean and free of portland cement, lime or plaster. See Page 9 
for suggestions on Transit-Mixed Concrete. 



Materials 



Mixing 
Time 



A typical 1:2:4 LUMNITE Concrete from 1 Day to 1 Year 

3 Mo. 6 Mo. 



1 Day 



7 Days 2 8 Days 



1 Year 



3441 psi 



4391 



4462 



4813 



4846 



5072 



LUMNITE Concrete is Ready for Full Service at 24 Hours 



United States Engineer Office, Corps 
of Engineers, U. S. Army, specified 
LUMNITE Concrete for gate tracks 
on Ohio River Locks, after several 
years' experience with LUMNITE 
in similar service. 




Page 6 



Methods for Making Overnight Concrete 



Proportions 

oi Mix 



Curing 



Time of 
Curing 



Mass 
Concrete 



Concrete made of 1 part LUMNITE, approximately 2 parts sand and 4 
parts coarse aggregate is satisfactory for most structural purposes. Pro- 
portion of fine and coarse aggregate should be adjusted to give greatest 
workability. Leaner mixes should be avoided as they may require an 
excessive amount of mixing water. Richer mixes are usually unnecessary 
and uneconomical. They should be used only for concrete of small di- 
mensions. For floor mixes see the paragraph on proportions under the 
heading "LUMNITE Concrete Floors" on Page 10. 

Mortars made of 1 part LUMNITE and 2 T / 2 parts sand meet most of the 
ordinary requirements of construction. Richer mixes should not be 
used except in very thin sections. 

Proper curing of LUMNITE concrete is essential. The curing of 
LUMNITE concrete differs from the curing of portland cement concrete 
because of the rapidity of hardening of LUMNITE. Concrete made with 
LUMNITE must be cured within 24 hours after mixing whereas curing 
of portland cement concrete is continued for several days. 

Curing is accomplished by spraying the surface of the concrete with 
water. No other method is equally effective. Do not cure by flooding 
the surface, or by covering with wet burlap, sawdust, sand or other 
materials. Steam curing should not be used. 

Under average conditions, curing water will be required about 6 hours 
after mixing. In warm, dry weather it may be required before 6 hours 
and in cold, damp weather as late as 10 or 12 hours. Curing water 
applied too soon will lower the surface strength of concrete. 

The time for first application of curing water may be determined by 
rubbing the surface with a moistened finger. IF THE FINGER IS 

CLEAN AFTER THE RUBBING, SPRINKLING SHOULD START. 
IF THE FINGER IS SOILED BY THE TEST, SPRINKLING 
SHOULD BE WITHHELD. 

The rapid hardening of LUMNITE is accompanied by the generation of 
appreciable heat. In large masses it is desirable that provision be made 
for the dissipation of this heat. This may be accomplished in several ways. 

The concrete may be deposited in successive layers no more than 15 
inches thick, allowing 24 hours between the pouring of the layers. Or, 
provision may be made for cooling the interior of the mass during the 
hardening of the concrete. Another means of achieving the same end 
is to place plumb stones in the concrete as it is poured. These large stones 
take up the heat of hydration and thus reduce the internal temperature 
of the concrete. The resulting concrete is cyclopean concrete which 
has long been used for massive work. Cyclopean concrete is decidedly 
economical as the volume of mixed concrete required for the structure 
may be appreciably reduced. 







A RUSH JOB ON A COLD WEEK-END 
The heavy foundation for this large ball 
mill had to be placed with least possible 
delay. LUMNITE concrete was used be- 
cause: 

1. LUMNITE concrete is stronger 
than any other kind of concrete at 



24 h 



ours. 



2. LUMNITE concrete can be placed 
in freezing weather with minimum 
protection and without artificial 
heat. 




Placing of the LUMNITE concrete on this job was started at 1 1 A.M. Sunda 
At 10 A.M. Monday, curing was completed, the foundation was ready f< 
mounting the machinery, which was then grouted in place with LUMNIT, 



i 



Overnight Concrete in Cold Weather 



Self-generated warmth of LUMNITE makes Overnight Concrete avail- 
able even in freezing weather. Costly protection and heating are noi 
needed. Only sufficient heat to keep the concrete above freezing tem- 
perature is required. Thin sections exposed to cold wind will lose heat 
rapidly and therefore require more protection than larger masses. 



The aggregate should be free from frost. Best results are obtained it 
the concrete is at a temperature between 5 F. and 70° F. when it 
leaves the mixer. The concrete should be kept at or near this tempera- 
ture range at least until it has set and begun to harden. 



The concrete should not be heated above 70° F. and heat should not be 
used to hasten the hardening action. Accelerators and "anti-freeze" 
admixtures must not be used with LUMNITE. The least amount of 
mixing water that will produce a workable mix should be used. 



Curing water is necessary in cold weather only if the concrete surfaces 
appear to dry out during the first 24 hours. 




Rush construction and maintenance jobs can be done overnight 



tvith LUMNITE 



regardless of iv eat her. 



Page 8 



C 

'-I 

c 
Q 

o 



C 

u 



Cold Weather Concrete 



100% 



4000 lbs. per sq. in 





Age in Days 

Comparison of gain in strength of LUMNITE concrete, concrete 
made with high-early-strength portland cement and normal port- 
land cement, mixed, placed and cured at 5 F. Designed strength 
of all concretes was 4000 psi. 



No other American-made 
same strength as LUMNITE 
conditions. 



cement will produce concrete of the 
in 24 hours — under any weather 










: 









Overnight Concrete in Hot Weather 



Heat accelerates the hardening of LUMNITE. In hot weather the 
atmospheric temperature may hasten the hardening of the concrete too 
much, causing quick set and lowered strengths. It is therefore essential 
for best results that the LUMNITE, aggregates and freshly placed con- 
crete he protected trom the direct rays of the sun. 

Sprinkling of the aggregates will lower their temperature. Forms should 

hi -tripped as soon as possible. Exposed surfaces of concrete should be 

ured by sprinkling freeh with water. I requent sprinkling lowers the 

temperature of the concrete. 



Page 9 



Transit-Mixed Concrete 



Because of the difficulty in removing partially hardened portland cement 
concrete from transit mixers there is danger of contamination of 
LUMNITE concrete with small quantities of portland cement. When 
LUMNITE concrete is prepared in transit mixers the following precau- 
tions should be observed. 

Truck mixers should be thoroughly cleaned to remove all portland ClCUItilltJ 



cement, and any other foreign material. Portland cement mixed with 
LUMNITE will cause quicker setting — in certain proportions the mix- 
ture will be flash-setting. Absolute cleanliness of equipment is very im- 
portant. The flushing water, used to clean out the mixers, should be 
discarded, and should NOT be used as part of the mixing water for 
the next batch. 



Prolonged mixing (more than 1 ]/ 2 minutes) may cause the LUMNITE 
to set too fast. // should not be mixed in transit. Transport to job and 
begin mixing just prior to dumping the concrete. 



Industrial Maintenance 

Machine bases of LUMNITE concrete can be completely installed ready 
for full load in 24 hours or less. Mounting of machines can be started 
a few hours after the concrete is placed. By the time the machines are 
ready for operation the LUMNITE concrete has the strength to with- 
stand load and vibration. 



Footings to support steel for building additions, floors which must be 
in place for essential production operations can be most quickly in- 
stalled with LUMNITE concrete. 



Equipment 



Mixing 



Machine Foundations of LUMNITE 
Concrete Ready for Full Load in 
24 hours. 




Page 10 



Lumnite Concrete Floors 

Floors and floor toppings of LUMNITE concrete are ready for use the 
day after placing — even when subject to heavy loads. Week-end main- 
tenance jobs are quickly completed with LUMNITE. 

(For information on floors exposed to corrosive conditions see the book- 
let, "LUMNITE for Corrosion -Resistant Concrete.") 



One-Course Floors 



Overn 



Concrete, given on the preceding pages, should be followed. Details 
of curing and finishing are the same as described for LUMNITE Top 
Courses on the following pages. 

The proportions of mix generally used for monolithic LUMNITE con- 
crete floors are: 1 bag LUMNITE, 2 cubic feet sand, 3 to 3 T / 2 cubic 
feet coarse aggregate. The least amount of mixing water which will 
give a stiff but workable concrete should be used. 



Lumnite Top Courses for Concrete Floors 



A LUMNITE topping may be placed on an unhardened, freshly placed 
LUMNITE base but should not be placed on an unhardened base of 
Portland cement concrete. When LUMNITE is to be used for the top 
ourse on a new portland cement concrete slab the port land cement 
slab should be cured for several days before the LUMNITE topping 
is placed. 



PlQCinO * n orc ' er to obtain a satisfactory bond between the topping and old 

concrete it is important to remove entirely the surface of the old con- 
crete so as to expose a clean, dust -free, hard surface. The thickness of 
the topping on an old or hardened concrete base should be at least one 
and one-half inches with full thickness at the edge. A feather edge must 
not be allowed* 








Base Slob ^ld concrcte floors can be resurfaced with a LUMNITE top course. 

LUMNITE mikes a tough, wear-resistant surface, available in minimum 
time. The LUMNITE topping can be bonded securely to an old portland 
cement concrete slab. 







A LUMNITE floor carrying heavy 
loads in a carpet factory. Entire 
floor was placed on several week- 
ends — each new section ready for 
traffic Monday morning. 











The base should be moistened until it will not readily absorb any more 
water. It is common practice to apply LUMNITE grout on the base 
slab immediately before the top course is placed. Some contractors use 
a neat grout of LUMNITE and water. Others prefer a 1:1 or 1:2 mix 
of LUMNITE, sand and water. The grout should be thoroughly broomed 
and distributed over the surface. (If this treatment of the surface is 
done too far ahead of the placing of the topping, the grout will dry out 
and a satisfactory bond will not be obtained.) The mortar topping 
should then be spaded or worked into a homogeneous, dense mass, free 
from pockets. 



Clean, hard, well-graded aggregates arc necessary for successful results. MfltGlifllS 



The following proportions are generally used: 



Coarse sand (graded from dust to Y%") 
parts sand. 

Medium sand (graded from dust to 54") 
parts sand. 



Fine sand (graded from dust to l /g") 



1 part cement to 3 



1 part cement to 2 l / 2 



1 part cement to 2 parts 



Wh 



suggested that dust-free stone chips or pea gravel be added to the 
mix. Such mixes have been used in the proportions of 1:1:2, 
1:1 J4:2, 1:2:1, 1:2:2, depending on the size and character of 
the sand and coarse material. 

Note: All of the foregoing proportions allow for average bulking 
of the sands. 



and 
Proportions 



Page 1 2 



Mixing 
Water 



Finishing 



Add least quantity of water to give a stiff but workable mortar. The 
total water in the mix, including moisture in aggregates, should not 
exceed 5 gallons per bag of LUMNITE. With well-proportioned aggre- 
gates or when a power-float is employed for finishing, less water may 
be used. 

Screed the mortar with an accompanying tamping and criss-cross move- 
ment to insure maximum compacting and uniformity of surface. After 
screeding, use the wood float a minimum number of strokes. In many 
cases a wood float finish is all that is desired. For smoother surfaces wood 
floating is followed by steel trowelling. When trowelling is done too soon 
water is drawn to the surface, causing dusty surfaces that are weak and 
rapidly wear away under traffic. 



Wait after screeding and floating until the surface becomes somewhat 
dull in appearance before trowelling. In warm, dry weather trowelling 
should start sooner than in cool, damp weather. Under average condi- 
tions trowelling is done in from two to four hours after mixing. Some 
contractors have stated that LUMNITE toppings require less trowelling 
than portland cement floors. 

LUMNITE hardens very rapidly after the initial or first set. This 
necessitates rapid finishing of each section of the floor after it has begun 
to set. LUMNITE concrete cannot be retempered or trowelled after 
it has obtained its final set. 



Curing 



When free water rises to the surface it may be removed by belting or 
wiping the surface with a piece of dry burlap or other absorbent ma- 
terial. "Dryer mixtures" of cement or cement and sand generally cause 
surface scaling. 



Power Float: A power float is often employed for finishing LUMNITE 
concrete floors. Excellent results can be obtained because more 
coarse aggregate and less mixing water can be used. 



LUMNITE concrete floor surfaces should be cured by sprinkling as 
described in the general suggestions for curing LUMNITE concrete on 
Page 15. 



In large areas some portions of the surface will be ready for curing 
before others. Care should be taken to sprinkle with water only those 
areas that are hard enough to receive curing water. Curing water 
should be applied sparingly at first. Do not cure by ponding the sur- 
face or by covering with wet sawdust, burlap or other coverings. 



Page 1 3 




Special Uses of Lumnite 



LUMNITE grout is used for sealing rock seams and fissures or wherever GrOUtllUT 

pumped grout is desired. Its quick-hardening properties are highly ad- | #i n |p C 

vantageous in such work around dams, mines and tunnels. The resistance 
of the grout to the attack of corrosive ground waters is often an im- 
portant reason for the use of LUMNITE in this manner. 

LUMNITE grout for setting bed plates of heavy machinery and equip- IndUStlidl 



ment has the high 24-hour strength characteristic of all LUMNITE 
mortars. One day after placing, the grout is ready for full service. 

Best results will be had and the least cement used if a relatively dry 
mortar composed of 1 part LUMNITE and 2 l /z parts sand is used- 
Only sufficient mixing water should be added so the mortar can be packed 
under the bed plate. All exposed surfaces should be sprinkled as soon 
as the grout has set — usually in about 6 hours. The mortar should be 
kept moist for the next 10 to 14 hours. 



Quick-Setting Gunite Mixtures 



Certain materials added to LUMNITE greatly accelerate the set, fre- 
quently causing flash-set. This is true when portland cement is mixed 
with LUMNITE. Such mixtures should not be used for ordinary con- 
struction work, due to the difficulty in controlling the setting time and 
the fact that the lime content of the concrete is increased. When placed 
with a cement gun, however, LUMNITE-portland mixtures may solve 
difficult construction problems. 

In the cement gun, the water joints the cement at the nozzle of the 
gun. Flash-setting mixtures may be used as the gunite is in place before 
setting occurs. This method is convenient for meeting special conditions, 
such as shutting off water, sealing caissons, stopping seepage in rock 
seams and placing bulkheads to seal off mine fires. 

Railroad tunnel linings in which such quick-setting mixtures have been 
placed with a cement gun have been in service over 15 years. 
LUMNITE-Gunite linings are suggested for the repair of old con- 
crete linings and for new construction. The setting time of the mixtures 
can be adjusted to suit conditions, so that wet and leaking tunnel walls 
usually can be sealed without making other provision for the water than 
the application of the gunite coat. 



Grouting 



Page 1 4 




Equal parts of LUMNITE and portland are commonly used. The exact 
proportion of the cement mixture to give the desired time of set must 
be determined by trial batches with the portland cement to be used 
on the job. Different portland cements will give different results. The 
portland cement should be thoroughly mixed dry with the LUMNITE 
until a uniform color is obtained. The two or three parts of sand used 
with the cement mixture should be very dry. 

The water should be at a temperature between 70° F. and 100° F. 

Cooler water causes slower setting and slower hardening. The nozzle 

of the cement gun should be equipped with a water ring having not less j 

than 16 holes. 

The strength of the LUMNITE-portland mortars will be less at 24 
hours than that of an all-LUMNITE mortar. For maximum 24-hour 
strength LUMNITE should be used without portland cement or other 
admixture. 














T 



op 




Page 1 5 



SUMMARY 




SUGGESTIONS 




USING LUMNITE 



Proportions 



Mortar made of 1 part LUMNITE and Do not cure by wet coverings, such as 
2 l /z parts sand meets most ordinary burlap, sawdust, or sand as this reduces 



construction requirements. Richer mor- 
tar mixes should not be used except in 
very thin sections. 

Concrete made of 1 part LUMNITE 
with approximately 2 parts sand and 4 



surface strength and causes dusting. 

In mass concrete, forms should be re- 
moved as soon as concrete will support 
its own weight, to increase the surface 
area to be cured. Surfaces should be 



parts stone (or gravel) is satisfactory kept wet until concrete is 24 hours old. 



for most purposes. Leaner concrete 
mixes frequently require too much 
mixing water and should be avoided. 



Under average conditions curing water 
will be required about 6 hours after 
mixing. In warm, dry weather it may 



Richer concrete mixes are usually un- be required before 6 hours and in cold 



necessary and uneconomical. They 
should only be used for concrete of 
small dimensions. 

Mixing Water 
Use Least Amount Possible 

Concrete made with 5 gallons of mix- 



damp weather as late as 1 or 12 hours. 

Curing water applied too soon will 
lower the surface strength of concrete. 

The time for first application of curing 
water may be determined by rubbing 
the surface with a moistened finger. 



ing water per bag of LUMNITE will If the finger is clean after the rubbing, 
be more than twice as strong and more sprinkling should start. If the finger 
durable than concrete made with 10 is soiled by the test, sprinkling should 



gallons. 

For mortar, do not use more than 5 gal- 



be withheld. 

The application of curing water is very 



Ions of water and for concrete no more important when LUMNITE is used in 



than 7 gallons per sack of cement, in- 
cluding the moisture in the aggregates. 

Proper Curing Important 

Curing water should be applied by 



warm weather, in rich mixes, in large 
masses, and on large exposed surfaces 
where maximum surface strength is 



desired, such 
pavements. 



floors, sidewalks and 



spraying. Flooding the Steam curing or heating to hasten the 

hardening of LUMNITE should not be 



sprinkling or 

surface with curing water, especially 

at the start of curing, should be avoided. 



used. 




TUMNITE , 



A Special Cement for Special Purposes 



Industry uses LUMNITE for these special purposes: 



Overnight Concrete 



Structural concrete ready for full service within 24 hours of placing 



Corrosion -Resistant Concrete 



Structural concrete for floors, foundations, drains and linings subject 
to the action of many corrosive solutions and wastes. 



Refractory Concrete 



Concrete for high-temperature service made with LUMNITE as a 
binder for refractory aggregates. Used for monolithic construction 
of industrial furnaces, kilns, and other heating equipment and for 
precast refractory shapes. 



Stack and Chimney Linings 



Corrosion-resistant, refractory and insulating linings for steel stacks. 
Corrosion-resistant mortar for brick chimneys and linings. 



For Information on These Uses of LUMNITE Write: 



The Atlas Lumnite Cement Company 

United States Steel Corporation Subsidiary 



135 EAST 42nd STREET 



NEW YORK, N. Y 



RM-1 12 



[BLANK PAGE] 




CCA 



INTERNATIONAL 




United States Steel 



Chrysler Building, New York 



Corporation Subsidiary 

20S South La Salle Street, Chicago